Active thermal interposer device

ABSTRACT

A stand-alone active thermal interposer device for use in testing a system-in-package device under test (DUT), the active thermal interposer device includes a body layer having a first surface and a second surface, wherein the first surface is operable to be disposed adjacent to a cold plate, and a plurality of heating zones defined across a second surface of the body layer, the plurality of heating zones operable to be controlled by a thermal controller to selectively heat and maintain respective temperatures thereof, the plurality of heating zones operable to heat a plurality of areas of the DUT when the second surface of the body layer is disposed adjacent to an interface surface of the DUT during testing of the DUT.

RELATED APPLICATION(S)

This Application claims priority to U.S. Provisional Application No.63/121,532, filed Dec. 4, 2020, entitled, “Active Thermal Interposer,”which is also incorporated herein by reference in its entirety. Thisapplication is related to U.S. Pat. No. 9,291,667 entitled “AdaptiveThermal Control,” which is incorporated herein by reference in itsentirety. This application is related to U.S. patent application Ser.No. 17/531,649, filed Nov. 19, 2021, entitled “Active Thermal InterposerDevice” to Kabbani et al., which is incorporated herein by reference inits entirety.

FIELD OF INVENTION

Embodiments of the present invention relate to the field of integratedcircuit manufacturing and test. More specifically, embodiments of thepresent invention relate to systems and methods for active thermalinterposer devices.

BACKGROUND

It is common to subject integrated circuits, either packaged orunpackaged, to environmental testing as an operation in a manufacturingprocesses. Typically in such testing, the integrated circuit devices aresubject to electrical testing, e.g., “test patterns,” to confirmfunctionality while being subjected to environmental stress. Forexample, an integrated circuit is heated and/or cooled to itsspecification limits while being electrically tested. In some cases,e.g., for qualification testing, an integrated circuit may be stressedbeyond its specifications, for example, to determine failure pointsand/or establish “guard band” on its environmental specifications.

Traditionally, such testing has included placing one or more integratedcircuits and their associated test interface(s) and support hardwareinto an environmental chamber. The environmental chamber would heatand/or cool the integrated circuit(s) under test, known as or referredto as a device under test, or “DUT,” as well as the test interface andsupport hardware, to the desired test temperature. Unfortunately, use ofsuch test chambers has numerous drawbacks. For example, the limitsand/or accuracy of such testing may be degraded due to environmentallimits of the test interface circuits and/or devices. In addition, dueto the large volumes of air and mass of mounting structures andinterface devices required within an environmental test chamber, theenvironment inside such a test chamber may not be changed rapidly,limiting a rate of testing. Further, placing and removing DUTs andtesting apparatus into and out of such test chambers further limitsrates of testing, and requires complex and expensive mechanisms toperform such insertions and removals.

SUMMARY OF THE INVENTION

Therefore, what is needed are systems and methods for active thermalinterposer devices. What is additionally needed are systems and methodsfor active thermal interposer devices operable to control differentportions of a device under test to different temperatures. Further,there is a need for systems and methods for active thermal interposerdevices operable to control different portions of a device under test atdifferent heights to different temperatures. There is a still furtherneed for systems and methods for active thermal interposer devices thatare compatible and complementary with existing systems and methods oftesting integrated circuits.

In accordance with embodiments of the present invention, a stand-aloneactive thermal interposer device for use in testing a system-in-packagedevice under test (DUT), the active thermal interposer device includes abody layer having a first surface and a second surface, wherein thefirst surface is operable to be disposed adjacent to a cold plate, and aplurality of heating zones are defined across the second surface of thebody layer, the plurality of heating zones are operable to be controlledby a thermal controller to selectively heat and maintain respectivetemperatures thereof, the plurality of heating zones operable to heat aplurality of areas of the DUT when the second surface of the body layeris disposed adjacent to an interface surface of the DUT during testingof the DUT.

Embodiments include the above and further includes each heating zone ofthe plurality of heating zones includes resistive traces for providingheat responsive to a voltage/current signal applied thereto ascontrolled by the thermal controller.

Embodiments include the above and further include the body layer furtherincludes a plurality of pogo pin mechanical/electrical interfaces formating with corresponding pogo pins of a thermal array. The plurality ofpogo pin mechanical/electrical interfaces are operable to inputvoltage/current signals from the thermal array for supply to theplurality of heater zones and also operable to output temperature sensordata corresponding to the plurality of heater zones.

Embodiments include the above and further include a grounded shieldlayer disposed on top of the second surface of the body layer and on topof the plurality of heating zones, the grounded shield layer operable toisolate the DUT from electro-magnetic interference radiation resultantfrom energizing heating zones of the plurality of heating zones.

Embodiments include the above and further include a two-dimensionalidentification code viewable thereon and wherein the two-dimensionalidentification code is operable to be machine read and provides one of:calibration values for a resistance temperature detector of the activethermal interposer device, identification information for identifyingthe active thermal interposer device, and security information forauthenticating the active thermal interposer device.

Embodiments include the above and further include the body layer furtherincludes alignment features disposed on the first surface, the alignmentfeatures for providing alignment between power pins of the activethermal interposer device and pads of a thermal head of the testersystem, and wherein the thermal head includes the cold plate.

Embodiments include the above and further include wherein the alignmentfeatures include micro-alignment bushings.

Embodiments include the above and further include a plurality ofmechanical buttons for providing mechanical compliance between theinterface surface of the DUT and the plurality of heater zones. Eachmechanical button is disposed between the body layer and a respectiveheater zone of the plurality of heater zones. Further, each mechanicalbutton includes an array of spring loaded pogo pins.

Embodiments include the above and further include a kick-off mechanicalbutton disposed on the second surface of the body layer, the kick-offmechanical button including an array of spring loaded pogo pins andoperable to separate the interface surface of the DUT from the secondsurface of the body layer when a force applied there between is removed.

Embodiments include the above and further include the DUT includes amulti-chip module and wherein further the plurality of heating and/orcooling zones are operable to be selectively energized for selectivelyheating and maintaining temperatures of chips of the multi-chip moduleduring the testing of the DUT.

Embodiments include the above and further include a Peltier/TEC coolinglayer disposed on the first surface of the body layer.

Embodiments include the above and further include wherein the body layerfurther includes a plurality of pogo pin mechanical interfaces, theplurality of pogo pin mechanical interfaces operable to inputvoltage/current signals for supply to the plurality of heater zones andalso operable to output temperature sensor data corresponding to theplurality of heater zones and also operable to input signals to controlthe Peltier/TEC cooling layer.

In accordance with a method embodiment, a method of testing asystem-in-package device under test (DUT) using an automated handlersystem and a tester system includes using a handler, automaticallypicking up the DUT from a tray and automatically placing the DUT into asocket, using an optical sensor to determine if the DUT is alignedplanar with respect to its orientation within the socket, using thehandler, automatically picking up an active thermal interposer deviceand automatically placing the active thermal interposer device on top ofthe DUT within the socket wherein the automatically placing the activethermal interposer device includes using alignment features of theactive thermal interposer device and of the socket to align the activethermal interposer device, and using the optical sensor to determine ifthe active thermal interposer device is aligned planar regarding itsorientation within the socket and with respect to the DUT.

Embodiments include the above and further include wherein theautomatically picking up the DUT from a tray and automatically placingthe DUT into a socket is performed by a first pick-and-place head of thehandler and wherein further the automatically picking up an activethermal interposer device and automatically placing the active thermalinterposer device onto top of the DUT within the socket is performed bya second pick-and-place head of the handler.

Embodiments include the above and further include wherein theautomatically picking up an active thermal interposer device andautomatically placing the active thermal interposer device onto top ofthe DUT within the socket further includes using an optical reader toread a two dimensional identification code disposed on the activethermal interposer device wherein the two dimensional identificationcode provides information including one of: an identification of theactive thermal interposer device, thermal calibration data regarding theactive thermal interposer device, and authentication informationregarding the active thermal interposer device and further includingrelaying the information to the tester system.

In accordance with another method embodiment, a method of testing asystem-in-package device under test (DUT) using an automated handlersystem and a tester system, the method includes using a firstpick-and-place head of the handler, automatically picking up the DUTfrom a tray and automatically placing the DUT into a socket, and using asecond pick-and-place head of the handler, automatically picking up anactive thermal interposer device and automatically placing the activethermal interposer device onto top of the DUT within the socket whereinthe automatically placing the active thermal interposer device includesaligning the active thermal interposer device using alignment featuresof the active thermal interposer device and of the socket.

Embodiments include the above and further include wherein theautomatically picking up an active thermal interposer device andautomatically placing the active thermal interposer device onto top ofthe DUT within the socket further includes using an optical reader toread a two dimensional identification code disposed on the activethermal interposer device wherein the two dimensional identificationcode provides information including one of: an identification of theactive thermal interposer device, thermal calibration data regarding theactive thermal interposer device, and authentication informationregarding the active thermal interposer device and further includingrelaying the information to the tester system.

In accordance with a method embodiment, a method of testing asystem-in-package device under test (DUT) using an automated handlersystem and a tester system, the method including using the handler,automatically picking up the DUT from a tray and automatically placingthe DUT into a socket, using the handler, automatically picking up anactive thermal interposer device and automatically placing the activethermal interposer device on top of the DUT within the socket, whereinthe automatically placing the active thermal interposer device includesaligning the active thermal interposer device by using alignmentfeatures of the active thermal interposer device and of the socket,wherein the active thermal interposer device, the DUT and the socketeach have a respective two dimensional code disposed thereon foridentification, authorization and/or calibration purposes, and using anoptical reader to read the two dimensional codes disposed on the activethermal interposer device, the DUT and the socket.

In accordance with another method embodiment, a method of testing asystem-in-package device under test (DUT) using an automated handlersystem and a tester system, the method including using the handler,automatically picking up the DUT from a tray and automatically placingthe DUT into a socket, wherein the DUT is secured within the socket viafirst retention features disposed within the socket, using the handler,automatically picking up an active thermal interposer device andautomatically placing the active thermal interposer device on top of theDUT within the socket, wherein the active thermal interposer device issecured within the socket via second retention features disposed withinthe socket and wherein further if the active thermal interposer deviceis placed within the socket by the handler and the DUT is not within thesocket, then the retention features are operable to prevent the activethermal interposer device from contacting pins of the socket.

In accordance with embodiments of the present invention, a testingdevice for testing a system-in-package device under test (DUI) includesa stand-alone active thermal interposer device for use in testing theDUT and for coupling with a thermal controller, the active thermalinterposer device including a body layer having a first surface and asecond surface, wherein the first surface is operable to be disposedadjacent to a cold plate, and a plurality of heating zones definedacross a second surface of the body layer, the plurality of heatingzones operable to be controlled by a thermal controller to selectivelyheat and maintain respective temperatures thereof, the plurality ofheating zones operable to heat a plurality of areas of the DUT when thesecond surface of the body layer is disposed adjacent to an interfacesurface of the DUT during testing of the DUT, and a thermal head forcoupling to the thermal controller and operable to interface with theactive thermal interposer device during testing of the DUT, the thermalhead including: the cold plate, and an insulation cover for insulatingthe cold plate, wherein the insulation cover includes a compressed dryair (CDA) injection port for reducing condensation from the cold plate.

Embodiments include the above and further include a thermal interfacematerial layer disposed between the active thermal interposer device andthe cold plate for coupling thermal energy from the active thermalinterposer device to the cold plate.

Embodiments include the above and further include wherein the thermalinterface material layer comprises a plurality of cutouts configured toprevent a pick and place handler from adhering to the thermal interfacematerial layer.

In accordance with embodiments of the present invention, a testingarrangement for testing a system-in-package device under test (DUT), thearrangement including: a socket device for containing the DUT and forinterfacing with a load board, stand-alone active thermal interposerdevice for use in testing the DUT, the active thermal interposer deviceincluding: a body layer having a first surface and a second surface,wherein the first surface is operable to be disposed adjacent to a coldplate, and a plurality of heating zones defined across a second surfaceof the body layer, the plurality of heating zones operable to becontrolled to selectively heat and maintain respective temperaturesthereof, the plurality of heating zones operable to heat a plurality ofareas of the DUT when the active thermal interposer device is insertedinto the socket and the second surface of the body layer is disposedadjacent to an interface surface of the DUT, a thermal head operable tointerface with the active thermal interposer device during testing ofthe DUT, the thermal head including the cold plate, and a thermalcontroller for coupling with the active thermal interposer device tocontrol the plurality of heating zones and to control the cold plate,the thermal controller including firmware operable to perform thermalregulation during testing of the DUT, the firmware operable to: obtainfirst temperatures which are of the cold plate from a temperature sensorof the cold plate, obtain second temperatures of the bottom surface ofthe active thermal interposer device for each heating zone thereof usingrespective resistance temperature detectors, obtain third temperaturesof each area of the DUT provided the DUT is active and circuitry on theload board is operable to collect a junction temperature for each areaof the DUT, based on the first temperatures, perform an outer slowerloop to regulate a fan speed (for air control) or a fluid regulationvalve (for liquid/refrigerant control) of the cold plate, and based onthe second and third temperatures, perform an inner faster loop toregulate heater control/Peltier control of the plurality of heatingzones of the active thermal interposer device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention. Unless otherwise noted, the drawings may not be drawn toscale.

FIG. 1A illustrates an exemplary block diagram of elements of anautomated test system environment that may serve as a platform forembodiments in accordance with the present invention.

FIG. 1B illustrates a plan view of an exemplary cold plate side activethermal interposer thermal interface material, in accordance withembodiments of the present invention.

FIG. 1C illustrates a perspective view of an exemplary test system, inaccordance with embodiments of the present invention.

FIG. 1D illustrates an exemplary testing system including the roboticmechanisms for automatically picking and placing a DUT into the socketand also for picking an active thermal interposer device and placing itinto the socket with the DUT, in accordance with embodiments of thepresent invention.

FIG. 2 illustrates an exemplary block diagram of a novel active thermalinterposer device, in accordance with embodiments of the presentinvention.

FIG. 3 illustrates an exemplary block diagram cross sectional view of anovel active thermal interposer device, in accordance with embodimentsof the present invention.

FIG. 4 illustrates an exemplary block diagram cross sectional view of anovel active thermal interposer device, in accordance with embodimentsof the present invention.

FIG. 5 illustrates a schematic of an exemplary heating element, inaccordance with embodiments of the present invention.

FIG. 6 illustrates an exemplary computer-controlled method for testingcircuits of an integrated circuit semiconductor wafer, in accordancewith embodiments of the present invention.

FIG. 7 is an exemplary block diagram of a control system for thermalcontrol of a plurality of devices under test, in accordance withembodiments of the present invention.

FIG. 8 illustrates a block diagram of an exemplary electronic system,which may be used as a platform to implement and/or as a control systemfor embodiments of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in conjunction withthese embodiments, it is understood that they are not intended to limitthe invention to these embodiments. On the contrary, the invention isintended to cover alternatives, modifications and equivalents, which maybe included within the spirit and scope of the invention as defined bythe appended claims. Furthermore, in the following detailed descriptionof the invention, numerous specific details are set forth in order toprovide a thorough understanding of the invention. However, it will berecognized by one of ordinary skill in the art that the invention may bepracticed without these specific details. In other instances, well knownmethods, procedures, components, and circuits have not been described indetail as not to unnecessarily obscure aspects of the invention.

Some portions of the detailed descriptions which follow (e.g., method600) are presented in terms of procedures, steps, logic blocks,processing, and other symbolic representations of operations on databits that may be performed on computer memory. These descriptions andrepresentations are the means used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. A procedure, computer executed step, logicblock, process, etc., is here, and generally, conceived to be aself-consistent sequence of steps or instructions leading to a desiredresult. The steps are those requiring physical manipulations of physicalquantities. Usually, though not necessarily, these quantities take theform of electrical or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated in a computersystem. It has proven convenient at times, principally for reasons ofcommon usage, to refer to these signals as bits, values, elements,symbols, characters, terms, numbers, data, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the present invention,discussions utilizing terms such as “testing” or “heating” or“maintaining temperature” or “bringing” or “capturing” or “storing” or“reading” or “analyzing” or “generating” or “resolving” or “accepting”or “selecting” or “determining” or “displaying” or “presenting” or“computing” or “sending” or “receiving” or “reducing” or “detecting” or“setting” or “accessing” or “placing” or “testing” or “forming” or“mounting” or “removing” or “ceasing” or “stopping” or “coating” or“processing” or “performing” or “generating” or “adjusting” or“creating” or “executing” or “continuing” or “indexing” or “translating”or “calculating” or “measuring” or “gathering” or “running” or the like,refer to the action and processes of, or under the control of, acomputer system, or similar electronic computing device, thatmanipulates and transforms data represented as physical (electronic)quantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

The meaning of “non-transitory computer-readable medium” should beconstrued to exclude only those types of transitory computer-readablemedia which were found to fall outside the scope of patentable subjectmatter under 35 U.S.C. § 101 in In re Nuijten, 500 F.3d 1346, 1356-57(Fed. Cir. 2007). The use of this term is to be understood to removeonly propagating transitory signals per se from the claim scope and doesnot relinquish rights to all standard computer-readable media that arenot only propagating transitory signals per se.

Active Thermal Interposer Device

FIG. 1A illustrates an exemplary block diagram of elements of anautomated test system environment 100 that may serve as a platform forembodiments in accordance with the present invention. Test system 100comprises a device under test (DUT) 110, for example, an integratedcircuit device, a system in a package (SIP), and/or a multi-chip module(MCM). The device under test is typically packaged, but that is notrequired. A socket 105 is coupled to device under test 110, e.g.,utilizing package leads on the DUT 110, to send and receive test signalsand power to device under test 110. Socket 105 is typically coupled to,and tests, a single device under test 110 at a time, although that isnot required. Socket 105 may be mounted to, or coupled to, a load board(not shown) for electrically coupling the socket 105 to a testcontroller, e.g., for electrical testing of DUT 110.

In accordance with embodiments of the present invention, a novel activethermal interposer device 120 is coupled to the backside or top ofdevice under test 110. Active thermal interposer device 120 may becustomized for a specific design of device under test 110, in someembodiments. In some embodiments, there may be a thermal interfacematerial 122 between active thermal interposer device 120 and deviceunder test 110. Such a thermal interface material, if present, isdesigned to improve thermal coupling between active thermal interposerdevice 120 and device under test 110.

In some embodiments, active thermal interposer device 120 may comprise abase layer of aluminum nitride (AlN) with tungsten and/or molybdenumtraces. A high temperature co-fired ceramic (HTCC) process may beutilized. Such embodiments may be suitable for testing comparativelyhigher power devices. In some embodiments, a low temperature co-firedceramic (LTCC) process, e.g., comprising aluminum oxide (Al₂O₃) may beutilized. Such embodiments may be suitable for testing comparativelylower power devices.

Active thermal interposer device 120 is further coupled to a cold plate130. In some embodiments, there may be a thermal interface material 124between active thermal interposer device 120 and cold plate 130. Such athermal interface material, if present, is designed to improve thermalcoupling between active thermal interposer device 120 and cold plate130.

In an embodiment, a cooling fluid, e.g., comprising glycol, althoughother fluids, including air, may be used, is generally circulatedthrough cold plate 130. To adjust the temperature of the cold plate 130,the temperature of the cooling fluid may be adjusted, in someembodiments. In some embodiments, as illustrated in FIG. 1A, the flowrate of the cooling fluid may also be adjusted, e.g., increased,reduced, started, and/or stopped. For example, a speed of a pump and/orfan may be adjusted. In an embodiment, chiller 135 cools the coolingfluid, e.g., to −60 degrees C. The cooling fluid flows 137 to valve 132.Valve 132, under the control of thermal controller 145 via controlsignal 146, regulates the flow 133 of cooling fluid to cold plate 130,based on one or more temperature measurements 134. After cycling throughcold plate 130, the cooling fluid is returned 136 to the chiller 135.Cold plate 130 may also be air or gas cooled, in some embodiments. Inthis manner, thermal controller 145 may cool DUT 110 during testing viacooling action from chiller 135 and the cold plate 130.

In accordance with embodiments of the present invention, thermalcontroller 145 may implement some or all of the control processesdescribed in U.S. Pat. No. 9,291,667 entitled “Adaptive ThermalControl,” incorporated herein by reference in its entirety.

In some embodiments, cold plate 130 may comprise an evaporator and/orphase change cooling system. In such embodiments, chiller 135 maycomprise a compressor and/or radiator, for example.

Active thermal interposer device 120 functions to apply heat energy toone or more temperature regions of device under test 110. For example,each die of a multi-chip module device under test may be individuallytemperature controlled. To accomplish such heating, active thermalinterposer device 120 comprises one or more heating elements, as furtherdescribed below. The heating elements of active thermal interposerdevice 120 define the temperature regions of device under test 110. Insome embodiments, the heating elements may comprise resistive traces ona ceramic substrate. In some embodiments, the heating elements maycomprise a cartridge heater. In some embodiments, the heating elementsmay comprise cooling elements, e.g., Peltier devices or other forms ofthermoelectric coolers (TEC), capable of cooling as well. However, anysuitable heating and/or cooling technology, in any combination, is wellsuited to embodiments in accordance with the present invention. Activethermal interposer device 120 also functions to couple heat energy fromdevice under test 110 to cold plate 130 and/or to cooling elementswithin active thermal interposer device 120, in some embodiments.

Active thermal interposer device 120 further comprises one or moretemperature measurement devices, e.g., resistance temperature detectorsand/or thermocouples. The one or more temperature measurement devicesare configured to measure a temperature of a region of device under test110. The one or more temperature measurement devices may be locatedwithin or in close proximity to the heating elements of active thermalinterposer device 120. In some embodiments, active thermal interposerdevice 120 may comprise temperature measurement devices characterized asnot within or in close proximity to the heating elements of activethermal interposer device 120. In some embodiments, a load board maycomprise temperature measurement devices. Each of the one or moretemperature measurement devices sends a temperature signal 121 tothermal controller 145. Socket 105, device under test 110, activethermal interposer device 120, and cold plate 130 may be collectivelyknown as or referred to as a test stack when coupled together asillustrated in FIG. 1A.

Test system 100 further comprises a thermal controller 145. Thermalcontroller 145 sends control signals 1477 to power supply 140 to supplyelectrical power 141 to one or more heating elements of active thermalinterposer device 120. Each heating element of active thermal interposerdevice 120 may be individually controlled. Accordingly, there aretypically more power signals 141 than illustrated. There may be morethan one power supply, in some embodiments. Based on temperature signal121 from one or more of the plurality of temperature measurementdevices, thermal controller may control power supply 140 to change thepower supplied to a heating element. Power supply 140 may change avoltage level and/or pulse width modulate a voltage supplied to aheating element, in some embodiments. Thermal controller 145 alsocontrols the amount of heat energy extracted 136 from cold plate 130.For example, thermal controller 145 controls the temperature of coldplate 130. Thermal controller 145 controls value 132 based ontemperature signal 121.

It is to be appreciated that cold plate 130 extracts heat, throughactive thermal interposer device 120, from substantially all of deviceunder test 110. In addition, cold plate 130 typically has a largethermal mass, and does not change temperature quickly. Accordingly,heating elements of active thermal interposer device 120 may often berequired to overcome the cooling effect of cold plate 130, during DUTtesting, for example. In some embodiments, different regions of a deviceunder test 110 may be heated and/or cooled to different temperatures.For example, one region of device under test 110 may be heated to 100degrees C., e.g., via a heater within active thermal interposer device120, while another region of device under test 110 may be allowed tocool toward the temperature of cold plate 130 with no heat applied tosuch region by active thermal interposer device 120. Such differentialheating and/or cooling of different regions of device under test 110 mayproduce a thermal gradient across or between regions of device undertest 110, in some embodiments.

It is appreciated that active thermal interposer device 120 is aseparate device from cold plate device 130 and socket device 105. Activethermal interposer device 120 is typically customized for a particulardevice under test and/or socket combination, but that is not required.In this novel manner, since the active thermal interposer device is astand alone device, different active thermal interposer devices may beutilized with standard cold plates and/or a variety of sockets invarious combination to test a variety of devices. For example, afunctionally similar multi-chip module may have multiple versions withsimilar or identical pin layouts but a different physical arrangement ofchips. Testing of such a family could be performed with the same socketwith different active thermal interposer devices to account for adifferent physical arrangement of chips.

FIG. 1B illustrates a plan view of an exemplary cold plate side activethermal interposer thermal interface material 124, in accordance withembodiments of the present invention. Thermal interface material 124 isdesigned to improve thermal coupling between active thermal interposerdevice 120 and cold plate 130, and may typically be adhered to activethermal interposer 120 (FIG. 1A), in some embodiments. Thermal interfacematerial 124 may comprise indium foil coupled to an adhesive sheet, insome embodiments. In some embodiments, thermal interface material 124comprises a plurality of cutouts 126. The cutout(s) match the contactlocation(s) of pick and place vacuum suction heads, in some embodiments.The cutout(s) may provide clearance for such pick and place vacuumsuction heads in order to prevent a pick and place handler from adheringto the thermal interface material 124, e.g., when attempting to handlean active thermal interposer, e.g., active thermal interposer 120.

FIG. 1C illustrates a perspective view of an exemplary test system 150,in accordance with embodiments of the present invention. Test system 150comprises a plurality of test sleds, for example, exemplary test sled156. Test sled 156 comprises a plurality, e.g., six, cold plates 130.Test sled 156 is configured to accept a test board drawer 153, which maybe inserted into the main body of test sled 156. Test board drawer 153comprises a test board 152. Test board 152 comprises a plurality, e.g.,six, of stacks 154. Each of stacks 154 comprises a socket 105, a deviceunder test 110 and an active thermal interposer device 120. Stack 154may also include thermal interface materials 122 and/or 124, in someembodiments. Test sled 156 further comprises power distribution, andcouplings to power, electrical test signals, and cooling fluids. Testsled 156 is configured to couple the plurality of cold plates to thestacks 154 when test board drawer 153 is inserted into the test sled156. It is appreciated that the perspective of a test stack asillustrated in FIG. 1C is reversed with respect to the test stack asillustrated in FIG. 1A. For example, the cold plate 130 is on the top inFIG. 1C, while the cold plate 130 is illustrated on the bottom in FIG.1A.

A plurality of test sleds 156, e.g., 12, is configured to be placed introlley 158, for insertion into a test rack 159. When inserted into testrack 159, the necessary electrical power, test signals, and cooling aresupplied to each test stack comprising a cold plate 130, an activethermal interposer device 120, a device under test 110 and a socket 105to be asynchronously tested by test system 150. In this novel manner, upto, for example, 72, devices may be heated and/or cooled, andelectrically tested at the same time in a single test system 150.

FIG. 1D illustrates an exemplary testing system 170 including therobotic mechanisms for automatically picking and placing a DUT into thesocket and also for picking an active thermal interposer device andplacing it into the socket with the DUT, in accordance with embodimentsof the present invention. After placement into the socket, the DUT andthe active thermal interposer device are passed to a thermal head. Forexample, the thermal head comprises a cold plate, e.g., cold plate 130.In one embodiment, the thermal head contains 12 slots; each slotcontaining 6 sockets, therefore 72 DUTs with corresponding activethermal interposer devices can be tested simultaneously. After testing,the active thermal interposer devices may be reused to test other DUTs.Within the thermal head is contained the cold plates which come intocontact with the active thermal interposer device during testing.

Within embodiments of the present invention, the active thermalinterposer device is known as or referred to as a “stand alone” devicebecause it is not permanently attached to any other device within thetesting system, as with the prior art testing systems and environments.In other words, the active thermal interposer device, being customdesigned for the DUT, is actively picked and placed, as a stand alonepart, and inserted into the socket as described above. Therefore, inorder to redesign the testing system for use with another type of DUT,only the active thermal interposer device, the DUT and the socket needto be redesigned, while the remainder of the testing system, including acold plate, may be reused.

Regarding FIG. 1D, a first pick and place arm 171 retrieves a deviceunder test, e.g., DUT 110 of FIG. 1A, from a tray of DUTs 173, andplaces it into a socket, e.g., socket 105 (FIG. 1A) on a test board 176.The test board 176 may correspond to test board 152 of FIG. 1C. A secondpick and place arm 172 retrieves an active thermal interposer device,e.g., active thermal interposer device 120 of FIG. 1A, from a tray ofactive thermal interposer devices 174, and places the active thermalinterposer device on top of the DUT, which is already on test board 176.The pick and place arms 171, 172 may grasp the DUT and/or active thermalinterposer device via any suitable means, including, for example, bygrasping on sides and/or above and below, and/or via vacuum suction, insome embodiments.

FIG. 2 illustrates an exemplary block diagram of a novel active thermalinterposer device 200, in accordance with embodiments of the presentinvention. Active thermal interposer device 200 comprises a frame 205upon which other elements may be attached or mounted. Frame 205 maycomprise any suitable materials, for example, thermoplastics. Frame 205comprises tabs 235. Tabs 235 are configured for handling and/ormanipulation of active thermal interposer device 200, for example, byautomated grasping equipment and/or pick and place equipment. Aplurality of contact pads 240 may be located on tabs 235 for makingelectrical contact to active thermal interposer device 200. For example,contact pads 240 may be configured to mechanically and electricallycouple with pogo pins (not shown) to couple electrical power and/orthermal sensor signals to/from active thermal interposer device 200. Insome embodiments, the contact pads 240 may comprise pads of differentsizes and/or shapes, for example, to correspond to different currentcapacities. In accordance with embodiments of the present invention, theambient atmosphere near any pogo pins should be kept above the dew pointin order to minimize and/or reduce condensation, which may have adeleterious effect on contact reliability. In accordance withembodiments of the present invention, active thermal interposer device200 may comprise one or more compressed dry air (CDA) ports 260, whichmay be coupled to a source of dry air, and utilized to inject dry airinto the test stack in order to prevent condensation. Active thermalinterposer device 200 may comprise an insulative cover (not shown) tohelp prevent condensation, in some embodiments.

Active thermal interposer device 200 may comprise latches 255, in someembodiments. Latches 255 are configured to securely couple a deviceunder test (not shown) to the active thermal interposer device 200. Forexample, latches 255 may extend over a device under test and/or itssocket, and lock it into place. Active thermal interposer device 200 maycomprise alignment features 250, in some embodiments. Alignment features250 may comprise fiducial alignment markings and/or receptacles, forexample, micro-alignment bushings, e.g., alignment pin sockets 251, toassist and/or ensure alignment of active thermal interposer device 200into a test stack, as described with respect to FIG. 1A.

In accordance with embodiments of the present invention, the socket,e.g., socket 105 of FIG. 1A, and/or active thermal interposer device 200comprise features to prevent the active thermal interposer device 200from making undesired electrical contact with electrical contacts of thesocket if a device under test is not present. Such undesired contact maylead to detrimental voltages and/or currents from the active thermalinterposer device 200 coupled into test equipment via the socket and/orphysical damage to socket contacts. Locating contact pads 240 outside ofa footprint of a DUT, e.g., outside of a socket, may help to preventsuch undesired contact, in some embodiments.

In some embodiments, active thermal interposer device 200 may comprise abarcode 245, e.g., for identification purposes. Barcode 245 may compriseany suitable encoding, including two-dimensional barcodes, in accordancewith embodiments of the present invention. Barcode 245 may uniquelyidentify a particular active thermal interposer device 200, in someembodiments. Uniquely identifying a particular active thermal interposerdevice 200 may allow calibration information for the particular activethermal interposer device 200 to be retried from a database and utilizedduring testing with the particular active thermal interposer device 200,in some embodiments. In some embodiments, barcode 245 may be utilized torecord and track which particular active thermal interposer device 200is used for testing with a particular socket, e.g., socket 105 of FIG.1A, and/or is used for testing a particular device under test, e.g., DUT110 of FIG. 1A.

In some embodiments, barcode 245 may encode calibration parameters,e.g., for thermal sensors, corresponding to a particular active thermalinterposer device 200. For example, such encoding may eliminate a needto access a database to retrieve such information. Barcode 245 may beutilized to ensure that a correct active thermal interposer device 200is selected, installed, and/or used for a particular test. For example,barcode 245 may be utilized to authorize and/or authenticate aparticular active thermal interposer device for use in particularequipment and/or for use in a particular test. Barcode 245 may be readwhen an active thermal interposer device is picked up for placement,e.g., from a storage location, and/or when placed in a test stack. Insome embodiments, the information encoded on barcode 245 may beencrypted. For example, information may be encrypted and then encoded bya standard barcode encoding.

Active thermal interposer device 200 may comprise a plurality of activethermal regions or zones 210, 215, 220, 225, 230, in some embodiments.In some embodiments, there may be a single thermal region. Each thermalregion may correspond to a region of a device under test. For example,active thermal region 210 may correspond to a large die of a multi-chipmodule, which active thermal regions 215, 220, 225, and 230 correspondto other and/or smaller chips of the multi-chip module. In someembodiments, multiple thermal regions may correspond to a single die orchip.

Each of active thermal regions 215, 220, 225, and 230 are configured toselectively apply thermal energy to a device under test, e.g., DUT 110of FIG. 1A. The active thermal regions 215, 220, 225, and 230 are alsoconfigured to selectively extract thermal energy from a device undertest. The extraction of thermal energy may be via a coupling to a coldplate, e.g., cold plate 130 of FIG. 1A, and/or via a Peltier devicewithin the active thermal regions 215, 220, 225, and 230. Each activethermal region may be independently controlled to a differenttemperature.

FIG. 3 illustrates an exemplary block diagram cross sectional view of anovel active thermal interposer device 300, in accordance withembodiments of the present invention. In the embodiment of FIG. 3 , adevice under test 110 is illustrated at the top of the active thermalinterposer device 300. Device under test 110 is included forillustration, and is not a part of active thermal interposer device 300.Active thermal interposer device 300 comprises a heating element layer350, mounted to or on an active thermal interposer device base 305.Heating element layer 350 comprises a plurality of heating elementsconfigured to apply heat energy to device under test 110. The heatingelements may comprise resistive traces or other suitable types ofheaters. Active thermal interposer device 300 may also comprise coolingelements, e.g., Peltier devices, within heating element layer 350, insome embodiments. The plurality of heating and/or cooling elements arecoupled to a plurality of electrical signals 355, for providingcontrolled power to the heating and/or cooling elements. Heating elementlayer 350 may include low resistance traces, e.g., from electricalsignals 355 to the actual heating elements, in some embodiments. Heatingelement layer 350 also comprises one or more temperature measurementdevices, e.g., thermocouples, (not shown), which are coupled to controlelements via temperature a plurality of sense signals 352.

In accordance with embodiments of the present invention, active thermalinterposer device 300 may comprise a novel electromagnetic interference(EMI) shield layer 320. Each of the plurality of heating elements inlayer 350 may utilize currents of many tens of amperes, e.g., togenerate heating of hundreds of watts during testing of a DUT. Inaccordance with embodiments of the present invention that utilizeswitching such currents to control temperature, e.g., pulse widthmodulation, such switching may induce unwanted electromagnetic noisesignals that are deleterious to the operation and/or test of integratedcircuits, e.g., device under test 110 of FIG. 1A, coupled to the activethermal interposer device 300. In some embodiments, EMI shield layer 320comprises a solid layer of conductor, e.g., conductive traces similar tothose utilized in heating element layer 350. In some embodiments, EMIshield layer 320 comprises a grid of conductive elements. The grid maybe sized to attenuate desired wavelength(s) of electromagneticinterference. EMI shield layer 320 may have an electrical connection325, e.g., to ground, in some embodiments.

Referring now to FIG. 5 , FIG. 5 illustrates a schematic of an exemplaryheating element 500, in accordance with embodiments of the presentinvention. Heating element 500 is well suited to use in active thermalinterposer device 120 (FIG. 1A). Heating element 500 may be powered by avoltage/current drive signal, and comprises two resistive heatingelements 510 and 520. Heating elements 510 and 520 may compriseresistive traces on a ceramic substrate, in some embodiments. Heatingelements 510 and 520 comprise resistive traces in a generally serpentinepattern, although the straight traces illustrated are not required. Thetraces may have a substantially curved nature, in some embodiments.Heating elements 510 and 520 are close together, for example, as closeas allowed by design rules for the technology, including currentcarrying capacity and insulative separation requirements. Heatingelements 510 and 520 may be operated together while phase reversed. Forexample, in the illustration of FIG. 5 , current may flow from top tobottom in heating element 510, and from bottom to top in heating element520. In this novel arrangement, electromagnetic fields generated byswitching of currents within heating element 510 may be substantiallycanceled by inverted electromagnetic fields generated by switching ofcurrents within heating element 520, reducing deleteriouselectromagnetic interference. If elements of heating elements 510 and520 comprise parallel elements, capacitive coupling may be beneficial aswell, e.g., reducing inductance in the resistive heating elements.

Referring once again to FIG. 3 , active thermal interposer device 300comprises a top thermal layer 340. Thermal layer 340 functions to coupleheat energy from heating element layer 350 to a device under test andvice versa. Thermal layer 340 is non conductive, in some embodiments.Thermal layer 340 should have a high degree of co-planarity in order tofacilitate good thermal conduction to a device under test, in someembodiments.

Active thermal interposer device 300 should be compatible andcomplementary with conventional elements of integrated circuit testequipment. In some embodiments, active thermal interposer device 300 maycomprise a blowoff line passthrough port 370. Blowoff line passthroughport 370 couples to a conventional blowoff line, as is typically used tobreak a seal or kick off a device under test, prior to removing thedevice under test from the test system. For example, blowoff linepassthrough port 370 mates with a blowoff line port of a conventionalcold plate, e.g., cold plate 130 of FIG. 1A. There may be a plurality ofblowoff line passthrough ports 370 in an instance of active thermalinterposer device 300, for example three arranged in an equilateraltriangle, in some embodiments. A blowoff line passthrough port 370typically extends through active thermal interposer device 300.

Active thermal interposer device 300 may also or alternatively comprisea device under test pin lift port 330, in some embodiments. Device undertest pin lift port 330 may be aligned with a similar port or channel ina cold plate, e.g., cold plate 130 of FIG. 1A. Device under test pinlift port 330 enables a device under test lift pin 335 to raise a deviceunder test above the top of the active thermal interposer device 300.The lift pin 335 typically extends from or through a cold plate, e.g.,cold plate 130 of FIG. 1A, and/or from a chuck mechanism (not shown). Inaccordance with some embodiments of the present invention, the lift pin335 may be lengthened, in contrast to a conventional lift pin, toaccount for the thickness of active thermal interposer device 300. Theremay be a plurality of pin lift ports 330 in an instance of activethermal interposer device 300, for example three arranged in anequilateral triangle, in some embodiments. A pin lift port 330 typicallyextends through active thermal interposer device 300.

Active thermal interposer device 300 may also or alternatively comprisea device under test air-powered kick off device 360. Kick off device 360comprises a kick off piston 364 that selectively pushes against DUT 110in response to pressure applied via compressed dry air (CDA) port 366.Active thermal interposer device 300 may also or alternatively comprisea device under test spring loaded kick off device 380. Device under testspring loaded kick off device 380 comprises a spring 382 that pushespiston 384 to push against DUT 110. A force exerted by spring 382 may becontrolled, in some embodiments. For example, spring 382 may beconstrained by a releasable latch mechanism, in some embodiments. Inother embodiments, spring 382 may comprise memory wire, for example,which expands in response to an applied voltage. In some embodiments,spring 382 may not be controlled. For example, spring 382 may alwaysapply a force against DUT 110. When, for example, a retention latch,e.g., latch 255 of FIG. 2 , is released, spring 382 may act, forcingpiston 384 against DUT 110, providing sufficient force to dislodge DUT110 from active thermal interposer device 300.

It is appreciated that multi-chip modules often comprise integratedcircuit devices of differing heights or thickness. FIG. 4 illustrates anexemplary block diagram cross sectional view of a novel active thermalinterposer device 400, in accordance with embodiments of the presentinvention. Active thermal interposer device 400 is configured tomechanically and thermally couple to a multi-chip module comprisingintegrated circuit devices of differing heights or thickness. FIG. 4illustrates a multi-chip module device under test comprising a substrate410, for example a printed wiring board or a ceramic substrate, anintegrated circuit packaged in a ball grid array (BGA) 420, and anotherintegrated circuit 430 packaged in a lower profile package, e.g., aplastic-leaded chip carrier (PLCC) or a “glop top” conformal coating.Package 420 is the tallest structure of the multi-chip module. Elements410, 420 and 430 are illustrated for context, and are not a part ofactive thermal interposer device 400.

Elements 305, 350, 320 and 340 are as previously described with respectto FIG. 3 , and may be described as or referred to as a test stackand/or thermal stack. Elements 350, 320 and 340 may correspond tothermal region 210 of FIG. 2 , for example. Elements 350′, 320′, and340′ have corresponding functions to elements 350, 320 and 340, and maybe described as or referred to as a (different) thermal stack. Elements350′, 320′, and 340′ may correspond to thermal region 230 of FIG. 2 ,for example. In general, elements 350′, 320′, and 340′ may be the samethickness as the corresponding elements 350, 320 and 340, but that isnot required. In contrast to elements 350, 320 and 340, elements 350′,320′, and 340′ are mounted on top of button 440. Button 440 comprises aplurality of pogo pins 460 and optional retention mechanism 450. Button440 is configured to raise (in the configuration of FIG. 4 ) elements350′, 320′ and 340′ so that top thermal layer 340′ is in good thermalcontact with integrated circuit package 430.

The plurality of pogo pins 460 push heating element layer 350′, EMIshield layer 320′ and top thermal layer 340′ up so that top thermallayer 340′ is in good thermal contact with integrated circuit package430. The plurality of pogo pins 460 also couple electrical signals toheating element 350′ and EMI shield layer 320′. Optional retentionmechanism 450 may keep elements 350′, 320′, and 340′ from rising toofar, for example, when a DUT is removed. It is appreciated that heatingelement layer 350′ may comprise contact pads to couple with pogo pins460. Heating element layer 350 may comprise similar pads, or may utilizea different mechanism to make electrical coupling(s) with a testapparatus, in embodiments. In accordance with embodiments of the presentinvention, a single active thermal interposer device may comprisemultiple thermal stacks on multiple buttons at different heights.

FIG. 6 illustrates an exemplary computer-controlled method 600 fortesting circuits of an integrated circuit semiconductor wafer, inaccordance with embodiments of the present invention. Method 600 may bepracticed by test system 170 as described in FIG. 1D, in someembodiments. In 610, a handler device places a device under test, e.g.,DUT 110 of FIG. 1A, into a socket, e.g., socket 105 of FIG. 1A, andchecks if the DUT is aligned via an out of position (OOP) sensor. In620, the handler places the active thermal interposer device, e.g.,active thermal interposer device 120 of FIG. 1A, on top of the DUT. Thealignment features in the socket and on the active thermal interposerdevice, e.g., 250 of FIG. 2 , assist in placing the active thermalinterposer device on top of the DUT. In 630, after the active thermalinterposer device is placed, a second OOP check is performed to ensurethat the active thermal interposer device is placed in a planar fashionand is not tilted or otherwise misaligned.

FIG. 7 is an exemplary block diagram of a control system 700 for thermalcontrol of a plurality of devices under test, in accordance withembodiments of the present invention. The control elements of controlsystem 700, e.g., active thermal interposer device heating/coolingcontrol 740 and/or cold plate control 750, may correspond to thermalcontroller 145 of FIG. 1A, in some embodiments. Device under test (DUT)710 may have multiple zones of varying heights for temperature control,for example, zone 1 712, zone 2 714, and zone 3 715. An on-chip and/orin-package temperature measurement 718 is accessed, if available. Insome embodiments, a temperature measurement from one or more temperaturesensors on a load board may be accessed. It is desirable to access anon-chip, in-package, and/or load board temperature measurementcorresponding to each zone. Any suitable on-chip, in-package, and/orload board temperature measurement device(s) may be utilized, e.g., aband gap, a ring oscillator, and/or a thermocouple.

Active thermal interposer device 720 is thermally coupled to deviceunder test 710. Active thermal interposer device 720 comprises multipleheating and/or cooling zones to correspond to the multiple zones ofdevice under test 710. In some embodiments, some heating and/or coolingzones of active thermal interposer device 720 may be mounted on buttonsto account for different heights of the multiple zones of device undertest 710, as previously described with respect to FIG. 4 . A temperaturemeasurement of cold plate 730 and one or more temperature measurementsof each active thermal interposer device zone may be accessed at 738,728, and/or 718.

Active thermal interposer device 720 is thermally coupled to a coldplate, e.g., cold plate 130 of FIG. 1A, e.g., via thermal interfacematerial 732. A temperature measurement 738 of cold plate 730 made bycold plate temperature sensor 731 is accessed.

The several temperature measurements, e.g., 718, 728, 738 are inputs toactive thermal interposer device heating/cooling control 740. Control740 generates one or more control outputs for each zone of activethermal interposer device 720 to achieve a desired temperature for eachof such zones. Control 740 also produces an output 744 that is input tocold plate control 750. Cold plate control 750 is configured to achievea desired temperature of cold plate 730. Cold plate control 750 outputsa control signal 752 that controls operation of fan speed and/or coolantvalve 754.

In accordance with embodiments of the present invention, one or both ofactive thermal interposer device heating/cooling control 740 and/or coldplate control 750 may utilize dual loop proportional-integral-derivative(PID) algorithms that are configured to utilize both heating and coolingelements to control a desired temperature for each zone of the deviceunder test 710. For example, a first control loop may control a fanspeed (for air control) and/or a fluid regulation valve (forliquid/refrigerant control) of the cold plate to control a temperatureof the cold plate 730 as measured by cold plate temperature sensor 731.A second control loop may operate relatively faster than the firstcontrol loop to control temperatures of each zone of active thermalinterposer device 720. As previously presented, each zone of activethermal interposer device 720 may comprise heating and cooling elements,in some embodiments.

FIG. 8 illustrates a block diagram of an exemplary electronic system800, which may be used as a platform to implement and/or as a controlsystem for embodiments of the present invention. Electronic system 800may be a “server” computer system, in some embodiments. Electronicsystem 800 includes an address/data bus 850 for communicatinginformation, a central processor complex 805 functionally coupled withthe bus for processing information and instructions. Bus 850 maycomprise, for example, a Peripheral Component Interconnect Express(PCIe) computer expansion bus, industry standard architecture (ISA),extended ISA (EISA), MicroChannel, Multibus, IEEE 796, IEEE 1196, IEEE1496, PCI, Computer Automated Measurement and Control (CAMAC), MBus,Runway bus, Compute Express Link (CXL), and the like.

Central processor complex 805 may comprise a single processor ormultiple processors, e.g., a multi-core processor, or multiple separateprocessors, in some embodiments. Central processor complex 805 maycomprise various types of well known processors in any combination,including, for example, digital signal processors (DSP), graphicsprocessors (GPU), complex instruction set (CISC) processors, reducedinstruction set (RISC) processors, and/or very long word instruction set(VLIW) processors. Electronic system 800 may also includes a volatilememory 815 (e.g., random access memory RAM) coupled with the bus 850 forstoring information and instructions for the central processor complex805, and a non-volatile memory 810 (e.g., read only memory ROM) coupledwith the bus 850 for storing static information and instructions for theprocessor complex 805. Electronic system 800 also optionally includes achangeable, non-volatile memory 820 (e.g., NOR flash) for storinginformation and instructions for the central processor complex 805 whichcan be updated after the manufacture of system 800. In some embodiments,only one of ROM 810 or Flash 820 may be present.

Also included in electronic system 800 of FIG. 8 is an optional inputdevice 830. Device 830 can communicate information and commandselections to the central processor 800. Input device 830 may be anysuitable device for communicating information and/or commands to theelectronic system 800. For example, input device 830 may take the formof a keyboard, buttons, a joystick, a track ball, an audio transducer,e.g., a microphone, a touch sensitive digitizer panel, eyeball scanner,and/or the like.

Electronic system 800 may comprise a display unit 825. Display unit 825may comprise a liquid crystal display (LCD) device, cathode ray tube(CRT), field emission device (FED, also called flat panel CRT), lightemitting diode (LED), plasma display device, electro-luminescentdisplay, electronic paper, electronic ink (e-ink) or other displaydevice suitable for creating graphic images and/or alphanumericcharacters recognizable to the user. Display unit 825 may have anassociated lighting device, in some embodiments.

Electronic system 800 also optionally includes an expansion interface835 coupled with the bus 850. Expansion interface 835 can implement manywell known standard expansion interfaces, including without limitationthe Secure Digital Card interface, universal serial bus (USB) interface,Compact Flash, Personal Computer (PC) Card interface, CardBus,Peripheral Component Interconnect (PCI) interface, Peripheral ComponentInterconnect Express (PCI Express), mini-PCI interface, IEEE 8394, SmallComputer System Interface (SCSI), Personal Computer Memory CardInternational Association (PCMCIA) interface, Industry StandardArchitecture (ISA) interface, RS-232 interface, and/or the like. In someembodiments of the present invention, expansion interface 835 maycomprise signals substantially compliant with the signals of bus 850.

A wide variety of well-known devices may be attached to electronicsystem 800 via the bus 850 and/or expansion interface 835. Examples ofsuch devices include without limitation rotating magnetic memorydevices, flash memory devices, digital cameras, wireless communicationmodules, digital audio players, and Global Positioning System (GPS)devices.

System 800 also optionally includes a communication port 840.Communication port 840 may be implemented as part of expansion interface835. When implemented as a separate interface, communication port 840may typically be used to exchange information with other devices viacommunication-oriented data transfer protocols. Examples ofcommunication ports include without limitation RS-232 ports, universalasynchronous receiver transmitters (UARTs), USB ports, infrared lighttransceivers, ethernet ports, IEEE 8394, and synchronous ports.

System 800 optionally includes a network interface 860, which mayimplement a wired or wireless network interface. Electronic system 800may comprise additional software and/or hardware features (not shown) insome embodiments.

Various modules of system 800 may access computer readable media, andthe term is known or understood to include removable media, for example,Secure Digital (“SD”) cards, CD and/or DVD ROMs, diskettes and the like,as well as non-removable or internal media, for example, hard drives,solid state drive s (SSD), RAM, ROM, flash, and the like.

Embodiments in accordance with the present invention provide systems andmethods for active thermal interposer devices. In addition, embodimentsin accordance with the present invention provide systems and methods foractive thermal interposer devices operable to control different portionsof a device under test to different temperatures. Further, embodimentsin accordance with the present invention provide systems and methods foractive thermal interposer devices operable to control different portionsof a device under test at different heights to different temperatures.Still further, embodiments in accordance with the present inventionprovide systems and methods for active thermal interposer devices thatare compatible and complementary with existing systems and methods oftesting integrated circuits.

Although the invention has been shown and described with respect to acertain exemplary embodiment or embodiments, equivalent alterations andmodifications will occur to others skilled in the art upon the readingand understanding of this specification and the annexed drawings. Inparticular regard to the various functions performed by the abovedescribed components (assemblies, devices, etc.) the terms (including areference to a “means”) used to describe such components are intended tocorrespond, unless otherwise indicated, to any component which performsthe specified function of the described component (e.g., that isfunctionally equivalent), even though not structurally equivalent to thedisclosed structure which performs the function in the hereinillustrated exemplary embodiments of the invention. In addition, while aparticular feature of the invention may have been disclosed with respectto only one of several embodiments, such feature may be combined withone or more features of the other embodiments as may be desired andadvantageous for any given or particular application.

Various embodiments of the invention are thus described. While thepresent invention has been described in particular embodiments, itshould be appreciated that the invention should not be construed aslimited by such embodiments, but rather construed according to the belowclaims.

We claim:
 1. A stand-alone active thermal interposer device for use intesting a system-in-package device under test (DUT), said active thermalinterposer device comprising: a body layer comprising a first surfaceand a second surface, wherein said first surface is operable to bedisposed adjacent to a cold plate; and a plurality of heating zonesdefined across the second surface of said body layer, said plurality ofheating zones operable to be controlled by a thermal controller toselectively heat and maintain respective temperatures thereof, saidplurality of heating zones operable to heat a plurality of areas of theDUT when said second surface of said body layer is disposed adjacent toan interface surface of said DUT during testing of said DUT.
 2. Thestand-alone active thermal interposer device as described in claim 1wherein each heating zone of said plurality of heating zones comprisesresistive traces for providing heat responsive to a voltage/currentsignal applied thereto as controlled by said thermal controller.
 3. Thestand-alone active thermal interposer device as described in claim 2wherein said body layer further comprises a plurality of pogo pinmechanical/electrical interfaces for mating with corresponding pogo pinsof a thermal array, said plurality of pogo pin mechanical/electricalinterfaces operable to input voltage/current signals from said thermalarray for supply to said plurality of heater zones and also operable tooutput temperature sensor data corresponding to said plurality of heaterzones.
 4. The stand-alone active thermal interposer device as describedin claim 2 further comprising a grounded shield layer disposed on top ofsaid second surface of said body layer and on top of said plurality ofheating zones, said grounded shield layer operable to isolate said DUTfrom electro-magnetic interference radiation resultant from energizingheating zones of said plurality of heating zones.
 5. The stand-aloneactive thermal interposer device as described in claim 1 wherein saidbody layer further comprises a two dimensional identification codeviewable thereon and wherein said two dimensional identification code isoperable to be machine read and provides one of: calibration values fora resistance temperature detector of the active thermal interposerdevice; identification information for identifying the active thermalinterposer device; and security information for authenticating theactive thermal interposer device.
 6. The stand-alone active thermalinterposer device as described in claim 1 wherein said body layerfurther comprises alignment features disposed on said first surface,said alignment features for providing alignment between power pins ofsaid active thermal interposer device and pads of a thermal head of saidtester system, and wherein said thermal head comprises said cold plate.7. The stand-alone active thermal interposer device as described inclaim 6 wherein said alignment features comprise micro-alignmentbushings.
 8. The stand-alone active thermal interposer device asdescribed in claim 1 further comprising a plurality of mechanicalbuttons for providing mechanical compliance between said interfacesurface of said DUT and said plurality of heater zones, wherein eachmechanical button is disposed between said body layer and a respectiveheater zone of said plurality of heater zones, and wherein further eachmechanical button comprises an array of spring loaded pogo pins.
 9. Thestand-alone active thermal interposer device as described in claim 1further comprising a kick-off mechanical button disposed on said secondsurface of said body layer, said kick-off mechanical button comprisingan array of spring loaded pogo pins and operable to separate saidinterface surface of said DUT from said second surface of said bodylayer when a force applied therebetween is removed.
 10. The stand-aloneactive thermal interposer device as described in claim 1 wherein saidDUT comprises a multi-chip module and wherein further said plurality ofheating zones are operable to be selectively energized for selectivelyheating and maintaining temperatures of chips of said multi-chip moduleduring said testing of said DUT.
 11. The stand-alone active thermalinterposer device as described in claim 1 further comprising aPeltier/TEC cooling layer disposed on said first surface of said bodylayer.
 12. The stand-alone active thermal interposer device as describedin claim 11 wherein said body layer further comprises a plurality ofpogo pin mechanical interfaces, said plurality of pogo pin mechanicalinterfaces operable to input voltage/current signals for supply to saidplurality of heater zones and also operable to output temperature sensordata corresponding to said plurality of heater zones and also operableto input signals to control said Peltier/TEC cooling layer.
 13. A methodof testing a system-in-package device under test (DUT) using anautomated handler system and a tester system, said method comprising:using said handler, automatically picking up said DUT from a tray andautomatically placing said DUT into a socket; using an optical sensor todetermine if said DUT is aligned planar with respect to its orientationwithin said socket; using said handler, automatically picking up anactive thermal interposer device and automatically placing said activethermal interposer device on top of said DUT within said socket whereinsaid automatically placing said active thermal interposer devicecomprises using alignment features of said active thermal interposerdevice and of said socket to align said active thermal interposerdevice; and using said optical sensor to determine if said activethermal interposer device is aligned planar regarding its orientationwithin said socket and with respect to said DUT.
 14. A method asdescribed in claim 13 further wherein said automatically picking up saidDUT from a tray and automatically placing said DUT into a socket isperformed by a first pick-and-place head of said handler and whereinfurther said automatically picking up an active thermal interposerdevice and automatically placing said active thermal interposer deviceonto top of said DUT within said socket is performed by a secondpick-and-place head of said handler.
 15. A method as described in claim13 wherein said automatically picking up an active thermal interposerdevice and automatically placing said active thermal interposer deviceonto top of said DUT within said socket further comprises using anoptical reader to read a two dimensional identification code disposed onsaid active thermal interposer device wherein said two dimensionalidentification code provides information including one of: anidentification of said active thermal interposer device; thermalcalibration data regarding said active thermal interposer device; andauthentication information regarding said active thermal interposerdevice and further comprising relaying said information to said testersystem.
 16. A method of testing a system-in-package device under test(DUT) using an automated handler system and a tester system, said methodcomprising: using a first pick-and-place head of said handler,automatically picking up said DUT from a tray and automatically placingsaid DUT into a socket; and using a second pick-and-place head of saidhandler, automatically picking up an active thermal interposer deviceand automatically placing said active thermal interposer device onto topof said DUT within said socket, wherein said automatically placing saidactive thermal interposer device comprises aligning said active thermalinterposer device using alignment features of said active thermalinterposer device and of said socket.
 17. A method as described in claim16 wherein said automatically picking up an active thermal interposerdevice and automatically placing said active thermal interposer deviceonto top of said DUT within said socket further comprises using anoptical reader to read a two dimensional identification code disposed onsaid active thermal interposer device wherein said two dimensionalidentification code provides information including one of: anidentification of said active thermal interposer device; thermalcalibration data regarding said active thermal interposer device; andauthentication information regarding said active thermal interposerdevice and further comprising relaying said information to said testersystem.
 18. A method of testing a system-in-package device under test(DUT) using an automated handler system and a tester system, said methodcomprising: using said handler, automatically picking up said DUT from atray and automatically placing said DUT into a socket; using saidhandler, automatically picking up an active thermal interposer deviceand automatically placing said active thermal interposer device on topof said DUT within said socket, wherein said automatically placing saidactive thermal interposer device comprises aligning said active thermalinterposer device using alignment features of said active thermalinterposer device and of said socket, wherein said active thermalinterposer device, said DUT and said socket each have a respective twodimensional code disposed thereon for identification, authorizationand/or calibration purposes; and using an optical reader to read saidtwo dimensional codes disposed on said active thermal interposer device,said DUT and said socket.